The invention concerns a method of monitoring patients with at least one electromedical implant.
Telemetry devices are generally employed for monitoring patients with an electromedical implant for the purposes of after-care, such as for example a cardiac pacemaker, a defibrillator, a cardioverter or another electronically actuated or controlled implant.
U.S. Pat. No. 5,752,976 for example discloses a method of the general kind set forth for monitoring patients having an electromedical implant. In that procedure a first data transmission takes place between the implant and an associated external apparatus which is generally referred to as the patient apparatus, that data transmission transmitting at least data from the implant to the external apparatus.
In order to collect those data and thus, for example, to be able to produce a patient profile for after-care purposes, but also in order to directly detect possible emergency situations and react thereto, a second data transmission is implemented between the external apparatus and a central storage arrangement for storage of first data which are transmitted from the implant to the external apparatus.
That second data exchange is effected by means of a telecommunication connection from the external apparatus to the central storage arrangement, the connection being made by way of a mobile radio network insofar as the external apparatus sends the data by way of the mobile radio network. In this case the use of a mobile radio network ensures that the mobility of the patient is limited as little as possible.
Devices operating as a modem are used for data transmission by way of the mobile radio network. This involves the disadvantage that on the one hand the relatively expensive modem devices are required for this kind of data transmissions, while on the other hand correspondingly high telephone charges are incurred because of the relatively low speed of transmission.
Therefore the object of the present invention is to provide a method of the kind set forth above, which permits simple and inexpensive monitoring of the patient.
The invention includes the technical teaching that it is possible to provide for particularly simple and inexpensive monitoring of the patient if the transmission of data to the central storage arrangement is effected by way of the portion, formed by the mobile radio network, of the telecommunication connection in the form of one or more SM-strings (by way of Short Message String).
SMS (Short Message Services) are generally offered by all mobile radio network operators. They are distinguished by particularly short transmission times and thus also the low charges incurred.
In preferred variants of the method according to the invention in that respect the time signature of an SM-string sent to the external apparatus by way of the telecommunication network is used for time synchronization of the external apparatus, whereby expensive additional measures for time synchronization of the external apparatus, for example separately calling up the current time from a separate piece of apparatus, for example a radiocontrolled clock and so forth, are not required.
Preferably in response to at least one transmission of a first SM-string from the external apparatus to the central storage unit a first acknowledgment SM-string is sent back to the external apparatus by the central storage unit and the time signature of the acknowledgment SM-string is used for time synchronization purposes. Thus, for example, when the external apparatus is switched on for the first time or when the external apparatus is switched on after a maintenance procedure, time synchronization can be effected. Time synchronization can also be effected however at any random or regular intervals during operation in order to prevent excessive deviating drift of the clock of the external apparatus.
It is also advantageous if the implant itself includes an SMS-capable receiver so that time synchronization of the implant can be effected independently of the external apparatus by way of SM-strings in the described manner. Alternatively, an internal clock of the implant can also be synchronized indirectly by means of the external apparatus.
In preferred embodiments, a transit time check is effected by the external apparatus prior to the time synchronization procedure. In that case, time synchronization is effected when the transit time between triggering of the transmission of the first SM-string and receipt of the associated first acknowledgment SM-string is within a predetermined transit time interval which is preferably at most one minute. That ensures adequate accuracy in terms of time synchronization.
In preferred variants of the method according to the invention for the purposes of locating the external apparatus, second SM-string are sent from the external apparatus to the central storage arrangement, those SM-string containing items of position information which are adequate for locating purposes, by way of the mobile radio network. That makes it possible to ascertain the position of the patient, for example in emergency situations in which the patient is now incapacitated, by means of the external apparatus which the patient has with him, so that suitable emergency measures can be initiated. It will be appreciated in this respect that this patient locating method can also advantageously. be used in itself, that is to say not just in connection with the use of SMS, but also with the known data transmission procedure. Items of positional information which are sufficient for locating purposes by way of the mobile radio network are contained for example in the field strength information with the associated numbers of the current and adjoined cells and the bit error rate.
Particularly advantageous variants of the method according to the invention are distinguished in that, at least when the external apparatus is switched on, a third SM-string is transmitted to a predetermined first central storage arrangement and the first central storage arrangement thereupon sends a second acknowledgment SM-string to the external apparatus. In that case the third SM-string contains information about the location of the external apparatus. The second acknowledgment SM-string contains control information for the external apparatus, with which a second central storage arrangement is possibly predetermined as the receiver for second data transmissions of the external apparatus. That makes it possible to select the respectively least expensive and/or fastest connection. Expensive, frontier-crossing connections can be avoided in that way.
It will be appreciated that during operation the third SM-string can also be emitted regularly automatically or at the instigation for example of the patient. It is likewise possible for emission of the third SM-string to be triggered by a central storage arrangement. It will be further appreciated that this variant of the method can also advantageously be used in itself, that is to say not just in conjunction with the use of SMS, but also with the known data transmission procedure.
In further advantageous embodiments of the method according to the invention, in the case of a predetermined first number of failed attempts at data transmission between the external apparatus and a central storage arrangement, data transmission is initiated in each case at most for a predetermined second number of attempts, to at least one further central storage arrangement. That ensures in a simple fashion that, in the event of failure of a central storage arrangement, the procedure switches automatically and sufficiently speedily to other central storage arrangements.
In other advantageous variants, in the event of a predetermined first number of failed attempts at data transmission between the external apparatus and a central storage arrangement, the data transmission is initiated in each case at most for a predetermined second number of attempts by way of at least one further telecommunication connection. It is thus possible, for example, to use another mobile radio network. If data transmission is tried by way of a fixed-line telecommunication network, then naturally there must be a suitable data transmission apparatus and a connection for making the telecommunication connection by way of the fixed-line telecommunication network. In that way it is possible, for example, to compensate for a fault in a mobile radio network or defects in the mobile radio device of the external apparatus.
It will be appreciated moreover that it is also possible to have a combination of the above-mentioned variant involving the selection of different central storage arrangements and the variant which involves using different telecommunication connections.
The present invention further concerns a monitoring system for patients which is distinguished in that the external apparatus is adapted for the transmission of the first data to the central storage arrangement by way of the portion, formed by the mobile radio network, of the telecommunication connection in the form of at least one Short Message String (SM-string), thereby ensuring simple and inexpensive operation of the system.